The initiation of sporulation was measured in the presence of excess glucose and ammonia, conditions under which normal sporulation remains suppressed. Sporulation was induced by a number of purine analogs, by the specific inhibitor of AMP synthesis hadacidin, the specific inhibitor of GMP synthesis inhibitor of GMP synthesis decoyinine, and the pyrimidine analog 6-azauracil. Optimal induction occurred under conditions under which growth was only partially inhibited. Sporulation was also observed under conditions of purine deficiency in purine auxotrophs, the leakiest mutants producing the highest sporulation frequency. A non-leaky purine mutant could also be caused to sporulate at different frequencies by changing the concentration of AICA supplied to the medium and allowing growth at different rates. Fructose bis-phosphatase was purified and its activity requirements were determined.